When to plant in Glendale, AZ
USDA Zone 9bGlendale, Arizona frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
A generous ~329-day season lets Glendale gardeners direct-sow more and still ripen long-maturity crops like melons and winter squash. Zone 9b is warm enough that Glendale can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
The average last spring frost in Glendale is now 7 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
YOUNGTOWN · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Glendale’s own odds, recorded at YOUNGTOWN.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Mar 4 | Feb 14 | Jan 21 | Nov 17 | Dec 2 | Dec 18 |
| 32°F | Feb 18 | Jan 20 | Dec 23 | Nov 28 | Dec 15 | Jan 7 |
| 28°F | Feb 1 | Jan 3 | Dec 13 | Dec 10 | Dec 29 | Jan 22 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Nothing new to sow or transplant outdoors in the next few weeks — a seasonal lull. Check the full-year calendar below for the next window.
Full-year planting calendar
Each bar is the exact window to take a planting action in Glendale, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 20 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Glendale planting FAQ
When is the last spring frost in Glendale, AZ?
Glendale's average last spring frost falls near January 20 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Glendale, AZ?
In Glendale, the first 32°F freeze of fall lands around December 15 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Glendale in?
Glendale is in USDA hardiness zone 9b. In zone 9b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Glendale?
There are roughly 329 frost-free days in Glendale (a long growing season), running from the average last frost around January 20 to the first fall frost near December 15.
When should I plant tomatoes in Glendale?
In Glendale, start tomato seeds indoors around November 25–December 9, then transplant seedlings outdoors around January 27 once the danger of frost has passed.
Never miss a window in Glendale
An email when it’s time to start seeds, transplant, and sow — timed to Glendale’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Phoenix · 10 km
- Sun City · 13 km
- El Mirage · 14 km
- Paradise Valley · 21 km
- Sun City West · 22 km
- Avondale · 28 km
- Surprise · 29 km
- Tempe · 29 km
Frost dates recorded at YOUNGTOWN, 12 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Glendale, AZ — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00029634. Retrieved from https://blissgarden.com/arizona/glendale.